[solved] Re: linux-next: build failure after merge of the perf tree

[Arnaldo Carvalho de Melo]

On Fri, Feb 23, 2024 at 04:50:47PM -0300, Arnaldo Carvalho de Melo wrote:
> On Thu, Feb 22, 2024 at 10:06:56AM +1100, Stephen Rothwell wrote:
> > Hi all,
> > 
> > After merging the perf tree, today's linux-next build (native perf)
> > failed like this:
> > 
> > util/bpf_skel/augmented_raw_syscalls.bpf.c:329:15: error: invalid application of 'sizeof' to an incomplete type 'struct timespec64'
> >         __u32 size = sizeof(struct timespec64);
> >                      ^     ~~~~~~~~~~~~~~~~~~~
> > util/bpf_skel/augmented_raw_syscalls.bpf.c:329:29: note: forward declaration of 'struct timespec64'
> >         __u32 size = sizeof(struct timespec64);
> >                                    ^
> > 
> > Caused by commit
> > 
> >   29d16de26df1 ("perf augmented_raw_syscalls.bpf: Move 'struct timespec64' to vmlinux.h")
> > 
> > This is a ppc64 le build.
> > 
> > I have used the perf tree from next-20240221 for today.
> 
> Ok, finally I managed to secure a ppc64 machine to test this and
> sometimes I reproduce just like you reported, but sometimes I can't do
> it, didn't manage to isolate what is that makes it fail sometimes, make
> -C tools/perf clean, nuking the O= target directory, etc, when I
> reproduce it:

So I think I see the problem, I now left the build directory with a
previous build from torvalds/master, then switched to the
perf-tools-branch and tried to build from there, without first removing
the old build, it fails:

  CLANG   /tmp/build/perf-tools-next/util/bpf_skel/.tmp/augmented_raw_syscalls.bpf.o
util/bpf_skel/augmented_raw_syscalls.bpf.c:329:15: error: invalid application of 'sizeof' to an incomplete type 'struct timespec64'
  329 |         __u32 size = sizeof(struct timespec64);
      |                      ^     ~~~~~~~~~~~~~~~~~~~
util/bpf_skel/augmented_raw_syscalls.bpf.c:329:29: note: forward declaration of 'struct timespec64'
  329 |         __u32 size = sizeof(struct timespec64);
      |                                    ^
1 error generated.
make[2]: *** [Makefile.perf:1161: /tmp/build/perf-tools-next/util/bpf_skel/.tmp/augmented_raw_syscalls.bpf.o] Error 1
make[1]: *** [Makefile.perf:264: sub-make] Error 2


Because it will use what was installed before in the build dir:

[acme@ibm-p9z-16-lp5 perf-tools-next]$ ls -la /tmp/build/perf-tools-next/util/bpf_skel/vmlinux.h 
-rw-r--r--. 1 acme acme 4319 Feb 23 14:59 /tmp/build/perf-tools-next/util/bpf_skel/vmlinux.h
[acme@ibm-p9z-16-lp5 perf-tools-next]$

And that one doesn't have 'struct timespec64':

[acme@ibm-p9z-16-lp5 perf-tools-next]$ grep timespec64 /tmp/build/perf-tools-next/util/bpf_skel/vmlinux.h 
[acme@ibm-p9z-16-lp5 perf-tools-next]$

If I remove that directory contents:

[acme@ibm-p9z-16-lp5 perf-tools-next]$ rm -rf /tmp/build/perf-tools-next/
[acme@ibm-p9z-16-lp5 perf-tools-next]$ mkdir /tmp/build/perf-tools-next/
[acme@ibm-p9z-16-lp5 perf-tools-next]$

And then try to build again:

make -k O=/tmp/build/perf-tools-next/ -C tools/perf install-bin

It works.

I reproduced the problem on x86_64, so, on this transition period, the
problem happens, probably we need to robustify the installation of
tools/perf/util/bpf_skel/vmlinux/vmlinux.h in the O= target directory,
but if you just make sure the build directory is clean before trying to
build it, this time, it should work, wdyt?

Ian, ideas?

- Arnaldo